Bond Breaker is based on real physical chemistry, which means by playing around with it, you’re actually doing science experiments. Last week, we looked at the Van der Waals forces, which pulls molecules together. This week, we’re going to go a little more basic.

Like Charges Repel

Whoa, we’re going very basic, eh? We’ve all heard the phrase ‘likes repel’ ever since we were in diapers. Two protons, both having positive charges, will push away from one another due to the electric force. The game includes this force, with each proton pushing on all the others:

“I just want personal space”

As you can see, they all try to get as far away from one another as possible. The calculations in the game are modeled completely after Coulomb’s Law, which tells us that the force between two charges is proportional to the inverse square of the distance between them. To put that in terms that anyone who hasn’t taken a course about Electromagnetism can understand: if you double the distance between the charges, the force will drop to just one quarter of what it was. It gets small fast. And this is why, in Bond Breaker, you can only get so close to another proton… and no closer.

“Whoa, whoa, whoa: don’t touch me.”

The connection between the force and distance can reveal itself in even more advanced ways, too. Take, for instance, this level:

It’s a new bonus level that I made just for this blog post, simply click the image above to play it in your browser. Once you give it a try: what does this level (or should I say, experiment) have to teach us about Coulomb’s Law? I’ll leave that to you, the player, to figure out.

And that’s one of my favorite things about making a game that stays true to the science: Each level is actually an experiment, which makes players scientists.

One of the best parts of making a game based on science is that while playing the game… you learn science. Even if you don’t mean to! Take, for instance, the Van der Waals force.

(If you haven’t played Bond Breaker yet, give it a go. It’ll make this all go down a little easier)

Van der Waals

The Electric Force, at its core, is pretty basic. You can sum it up with: “opposites attract, likes repel.” If you put two positive charges together, they’ll push away from each other. And if you put a positive near a negative, they’ll attract together. A neutral object, with no positive or negative charges, will be unaffected by the Electric Force.

In Bond Breaker, you can make a lot of ‘neutral’ object. A Hydrogen molecule, for instance, consists of two protons and two electrons. (+2) + (-2) = 0. Put two of them near each other, and the Electric Force shouldn’t do anything, right? Well, in Bond Breaker you can try that out! Below is a little level I made (just for you, blog-post-reader), to test out what happens when neutral molecules are near one another. Click it in your browser, and go play with the level (it’ll be called the ‘Bonus Level’).

These forces are what make molecules attract to one another (and form into liquids, say). The weakest form of VdW force is called the “London Dispersion Force,” and it’s what you encounter in the game.

London Dispersion Forces

‘Neutral’ molecules are not simply neutral. The positive and negative charges aren’t sitting right on top of one another. At any given moment, the molecule will have a dipole moment — meaning one side will be more positive, and one side will be more negative. Kind of like a bar magnet with a North pole and South pole. Imagine putting a bunch of magnets into a bag and shaking them. It won’t take long until they’re all stuck together.

With a molecules like Hydrogen that are very symmetrical, the dipole is completely random. Sometimes you’ll find the electrons more on the north side of the molecule, sometimes you’ll find them on the south side. And this makes the force pulling the molecules together very weak. But it’s still there.

With Bond breaker released (ahem, read about it here… never mind the Shocktopus screenshot… or here, or just go and play it here), I’ve gotten a chance to look back through some of my old files – and I came across this, the first prototype of Bond Breaker:

Catchy title, no?

Ah, the unnamed game. (I will say, I still love that subtitle.) Looks a little different from the current version, I’d say:

Needless to say, when you stumble across a digital time-capsule like this, it’s amazing to see how much has changed during the development of the game. The easiest thing to notice is the art style. So let’s take a little walk down screenshot lane. Can you tell the ‘old’ from the ‘new’??

The Repulsion Level

Prototypes are amazing things — they are the first rough draft of your game. You’re testing out ideas, and you use ‘programmer art,’ quick images that just make the game playable. So one of the big things you’ll notice is how basic all the art is in the prototype. Yellow squares instead of stars for goals, very basic walls, etc. You’ll also notice that the atoms were absolutely tiny on the screen, something I fixed in later versions.

Molecules

Molecules were the core of the game right from the beginning. I really enjoyed the feeling of tugging another atom around, with just a molecular bond tying you two together. If you go slow, you stick together, but if you go too fast, zooming around corners, you can split apart. With a little bit of practice, you could control your molecule pretty well — picking up protons, and depositing them elsewhere in the level.

Of course, in the original version, while the *physics* worked, the picture of the molecule was a little strange. Notice how it’s wider than it is long, making a strange oval around the two atoms. When you’re trying to make a quick draft, you need to ignore those little things. But in the final version, the molecule is shaped just as it should be. (Not to mention, you get a picture of a little electron zooming around you.)

The Menus

Unsung heroes of the game, menus are one of the last things I really care about when making a game. After all — nobody says “I wasn’t sure whether I liked the game or not… until I saw those amazing menus!” But as I’m sure you can see from the pictures below… the prototype menu needed some improvement.